Respiratory Health Program
The NIOSH Respiratory Health Program (RHP) advances NIOSH efforts to prevent work-related illness, improve workers’ respiratory health, and encourage multidisciplinary cooperation and collaboration across NIOSH programs and with external partners. RHP addresses a range of hazardous exposures and related health outcomes in every industrial sector. Adverse work-related health outcomes include:
- airways diseases (e.g., asthma, chronic obstructive lung disease [COPD]);
- interstitial lung diseases (e.g., coal workers’ pneumoconiosis [CWP], asbestosis, silicosis, berylliosis);
- respiratory infectious diseases (e.g., tuberculosis, avian and pandemic influenza, emerging respiratory infectious diseases);
- respiratory malignancies; and
- emerging respiratory diseases (already occurring or anticipated as a risk due to new exposures or other changes in the work environment).
RHP also seeks to improve workers’ respiratory health and devotes much effort to national and state-based occupational respiratory health surveillance.
The upper airways are air passages like the nose and sinuses that are close to where air enters and leaves the body. The lower airways include the windpipe, or trachea, and the progressively smaller air passages that carry air to the air sacs, or alveoli. Diseases of the airways are the most prevalent type of work-related chronic respiratory disease. Upper airway conditions like rhinitis and sinusitis are very common. Two lower airways diseases, chronic obstructive pulmonary disease (COPD) and asthma, are especially important problems. COPD refers to chronic bronchitis, emphysema, and combined presentations of these two diseases. It is a leading cause of morbidity and mortality in the United States and world-wide.
Asthma is an inflammatory airways disease causing episodic, reversible airways obstruction. “Work-related asthma” refers to both new-onset asthma caused by work and pre-existing asthma exacerbated by work and affects millions of workers each year. About 1 in 6 new asthma cases in adults are caused by occupational exposures, and 1 in 5 pre-existing cases experience exacerbation due to conditions at work. In recent years, diacetyl and related flavorings such as 2,3-pentanedione have been important emerging concerns, since they can cause disease affecting small airways called bronchioles.
The tissue that supports the lung’s air sacs (alveoli) is called the interstitium. Interstitial lung diseases damage the interstitium. They impair the ability of the lungs to take up oxygen from air and eliminate carbon dioxide into the air. Interstitial lung diseases frequently cause progressive scarring (fibrosis) of the lungs. Interstitial lung diseases can be caused by inhaling small particles of certain mineral or organic dusts and by inhaling some chemicals. Mineral dusts include asbestos, crystalline silica, coal mine dust, beryllium and others. Organic dusts include dusts contaminated with materials such as certain bacteria, fungi, or animal or bird proteins. Examples of interstitial diseases include asbestosis, silicosis, coal workers’ pneumoconiosis (black lung), chronic beryllium disease, hypersensitivity pneumonitis, and others. New causes of interstitial lung disease identified early in the 21st century include indium tin oxide and nylon flock. Idiopathic pulmonary fibrosis (IPF) in dental professionals is a recently-emerged work-related interstitial disease that is currently under study.
Respiratory Infectious diseases are caused by microbial pathogens such as viruses or bacteria. They can infect the upper and lower airways. These diseases can often be spread from person to person by aerosols of respiratory fluids generated by actions such as sneezing or coughing. Respiratory infectious diseases have become important occupational concerns. Since the anthrax attacks of 2001, the potential for exposure to weaponized airborne microbiological agents has become a reality for public service first responders and first receivers in health care facilities, as well as less obvious at-risk groups such as postal workers. Emerging respiratory infectious diseases such as Middle Eastern Respiratory Syndrome (MERS), pandemic influenza, and extensively drug-resistant tuberculosis (TB) have all been important concerns in recent years.
A variety of respiratory cancers can be caused by work exposures. These may not occur until many years after the initial work exposure. For example, mesothelioma, a cancer of the lining of chest, may not develop until the third or fourth decade after a worker is exposed to asbestos. Lung cancer is another type of respiratory cancer that can be caused by work exposures. Examples include secondhand tobacco smoke, asbestos, chromium, diesel exhaust, and silica.
Occupational respiratory disease surveillance involves ongoing, systematic collection, analysis, and dissemination of data about workers’ respiratory health and exposures to respiratory hazards. These data are needed to identify problem areas and track progress in addressing them. Population surveillance is especially important because work-related respiratory diseases are often unrecognized and thus unreported in individuals. Reasons include long time lags between hazardous exposures and development of disease and because diseases may be attributed to causes other than work exposures.